An empty rectangular container has a capacity of 153 ℓ and a height of 100 cm. At 9 a.m., Tap A is turned on to fill the container at a rate of 9 ℓ per minute for 19 minutes. After 3 minutes, Tap B is turned on to drain water from the container at a rate of 7 ℓ per minute for 6 minutes. What is the height of the water level in the container in the end? Give the answer in 1 decimal place.
1 ℓ = 1000 cm³ 
9 ℓ = 9000 cm³ 
7 ℓ = 7000 cm³ 
153 ℓ = 153000 cm³

Volume of water flowed in from Tap A
= 19 x 9000
= 171000 cm³

Volume of water from drained from Tap B
= 6 x 7000
= 42000 cm³

Volume of water left in the container
= 171000 - 42000
= 129000 cm³

Base area of the container
= 153000 ÷ 100
= 1530 cm² 

Height of water left in the container
= 129000 ÷ 1530
≈ 84.3 cm

Answer(s): 84.3 cm